Customer Unit Economics and Payback Review
Calculate auditable CAC, contribution LTV, and cohort payback, then identify the cash constraint and highest-impact fix.
Before & after
Same prompt, same agent — the only difference is the skill.
That's a good question. You'll want to calculate your customer acquisition cost, which is how much you spend on marketing and sales divided by new customers. Then calculate lifetime value — that's the total profit you make from an average customer over their relationship with you. The LTV to CAC ratio tells you if you're efficient. You'd also want to look at payback period and contribution margin. If LTV is at least 3x CAC, that's usually considered healthy. Do you have your sales and marketing spend handy? What's your average customer lifetime and monthly churn? What's your average revenue per customer? Once I have those numbers, I can help you calculate these metrics.
UNIT ECONOMICS ANALYSIS INPUTS (sample cohort: customers acquired Jul 2025): Customers in cohort: 47 Average contract value: 1,200 (annual) CAC spend (marketing + sales): 410 per customer OUTPUTS: LIFETIME VALUE (LTV): Gross margin per customer: 840 (70% of ACV) Average customer lifespan: 28 months Monthly retention rate: 94% LTV = 840 × (1 / 0.06 monthly churn) = 14,000 CUSTOMER ACQUISITION COST: 410 LTV:CAC RATIO: 34:1 (Healthy threshold: 3:1+) ✓ VERDICT: STRONG — unit economics are highly favorable PAYBACK PERIOD: 7 months Monthly contribution margin: 70 CAC recovery at: month 7 ✓ On-target (benchmark: <12 months) CONTRIBUTION MARGIN: 70% gross, 35% operating (after support/ops) REDFLAGS: None detected OPPORTUNITY: CAC could increase 4x and still maintain 3:1 LTV:CAC target RECOMMENDED ACTIONS: • Increase marketing spend (more efficient than current scale) • Explore higher-price customer segments • Monitor churn; current 6% annual is excellent NOTE: Analysis based on sample data and historical trends. Consult your finance team for strategic pricing or growth decisions. This is analytical output only, not financial advice.
About this skill
“Our LTV:CAC looks good, so why does acquiring customers keep draining cash?” This review checks the spend, margins, and retention behind the headline ratio, then calculates whether customers repay their acquisition cost within your cash limit.
What it does
- Reconciles fully loaded acquisition spend with eligible new customers, including sales-cycle timing and attribution limits.
- Separates revenue, gross profit, customer contribution, and acquisition cost so expenses are neither omitted nor counted twice.
- Calculates contribution LTV from customer cohorts or a clearly qualified churn model.
- Finds payback from cumulative retained-customer contribution instead of assuming every customer stays forever.
- Compares channels or segments on matched definitions and observation windows.
- Quantifies the binding constraint and the CAC, margin, or retention change needed to meet your target.
What you get
An auditable worksheet with formulas, inputs, assumptions, and a decision-focused readout. Incomplete data produces a provisional calculation with explicit limits and the few missing inputs that would materially change the conclusion.
Best for
Founders, finance leads, and growth operators deciding whether to scale acquisition, change pricing, or repair customer profitability in subscription, commerce, or service businesses.
SKILL.md preview
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name: customer-unit-economics-and-payback-review
description: >-
Calculates fully loaded CAC, customer contribution, contribution LTV, and retention-adjusted payback by reconciling costs and acquisition cohorts, then identifies the constraint on profitable growth. Use when the user says "calculate our unit economics", "is our LTV to CAC healthy?", "our ads look profitable but cash keeps falling", "how long until a customer pays back?", "compare acquisition channels", "check this LTV spreadsheet", or "can we afford to scale acquisition?".
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# Customer Unit Economics and Payback Review
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